Machine Guarding Standard

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    Machine

    Safeguardingat the Point ofOperation 

     A Guide for Finding Solutionsto Machine Hazards

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    About this documentMachine Safeguarding at the Point of Operation is an Oregon OSHA Standards andTechnical Resources Section publication.

    Thanks to the following individuals:

    Layout and design: Patricia Young, Oregon OSHA

    Editing and proong: Mark Peterson, DCBS Communications

    Questions or comments? We’d like to hear from you.• Technical questions about this publication?

    Contact Ken Langley: 503-947-7454, [email protected]

    Contact Craig Hamelund: 971-673-2875, [email protected] 

    • Comments or suggestions for improving this guide?

    Contact Stephanie Ficek: 503-947-7389, [email protected] 

    Piracy notice: Reprinting, excerpting, or plagiarizing this publication is ne with usas long as it’s not for prot! Please inform Oregon OSHA of your intention as a courtesy.

     Above:  Be Careful Near Machinery  poster, created by Robert Lachenmann (1936) for the Federal Art Project.Source: Library of Congress: Prints and Photographs Online Catalogue.

    mailto:[email protected]:[email protected]:[email protected]:[email protected]:[email protected]:[email protected]

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    Machine

    Safeguardingat the Point ofOperation 

     A Guide for Finding Solutionsto Machine Hazards

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    Table of Contents

    The importance of machine safeguarding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4

    Abrasive wheel grinder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

    Horizontal band saw  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9

    Vertical band saw. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10

    CNC turning machine. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11

    Compacting and baling equipment  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14

    Cut-off saws. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16

    Drill press . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18

    Ironworker  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19

    Jointer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20

    Metal lathe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21

    Wood lathe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23

    Milling machine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25

    Planer   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26

    Plastic injection molding  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27

    Portable abrasive grinder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28

    Portable belt sander   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29

    Portable circular saw  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30

    Portable jigsaw . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32

    Power press . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33

    Power press brake . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38

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    Power roll forming and bending machine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42

    Radial-arm saw . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44

    Robots . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45

    Belt sander . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .47

    Disk sander   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48

    Scroll (jig) saw  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50

    Shaper/router . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .51

    Shear  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .53

    Table saw . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .55

    Guarding power-transmission apparatuses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .57

    Lockout/tagout  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .58

    Risk-reduction hierarchy  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .59

    Training guidelines. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .61

    Basic safety principles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .62

    Glossary of terms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .63

    Oregon OSHA Services . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .64

    Table of Contents

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    The importance of machine safeguardingMost of us have heard the old adage about how machinery doesn’t discriminate betweenproduct and people – it will do the same to both. Many people discover this through unfortunatemeans: an injured machine operator sharing the details of his or her accident or a familymember reecting on the circumstances that took a loved one.

    Recent statistics that support the concern

    NationalContact with objects and equipment (caught in, on, or under equipment ormachinery only)

    • More than 700 fatalities per year 

    • More than 200,000 lost workday injuries per year

    Oregon

    Contact with objects and equipment(caught in and struck by/against)

    • 6 compensable fatalities per year 

    • 13.5 percent of all fatalities

    • 3,407 accepted disabling injuries

    Machines that have moving parts and workers who operate them have an uneasy relationship.Machines make workers more productive and enable them to form and shape material in waysthat would be impossible with hand tools. Technology can make machines safer, but as longas workers need machines to help them process material – to cut, shear, punch, bend, or drill – they will be exposed to moving parts that could harm them. Much of the danger occurs at thepoint of operation, where the work is performed and where the machine cuts, shears, punches,bends, or drills.

    About this guideThis guide focuses on point-of-operation hazards and safeguarding methods and offersa comprehensive look at equipment and machinery commonly found in various Oregonworkplaces. It does not specify all machine guarding requirements or all types of machineryor equipment. The reference section addresses typical hazards and guarding solutions relatedto power transmission devices, lockout/tagout, and general safety principles for operating ormaintaining machines and equipment.

    This guide also refers to many American National Standards. The American National StandardsInstitute (ANSI) publishes voluntary consensus standards on the care and use of machinery. ANSI standards provide guidance for complying with Oregon OSHA standards. ANSI standards

    are sometimes incorporated into Oregon OSHA regulations and employers are accountablefor complying with the version specied. Oregon OSHA generally recommends, however, thatemployers follow the most recent ANSI standards. Of course, all original equipment operatingmanuals (OEMs) and other manufacturer suggestions must be strictly adhered to.

    In addition to ANSI, the International Organization for Standardization (ISO) standards providerequirements for personnel safety in the design, construction, and integration of machinery.ISO standards are voluntary.

    Oregon fatalities

    Operator pulled into amachine by a moving belt

    Worker caught in anirrigation spool

    Lathe operator hit byrotating bar stock

    Operator caught in keyedshaft (loose-tting shirt

    contributed) Worker caught in a

    glue line conveyor 

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    Oregon OSHA standards related to machineryand machine guarding

    General Industry

    Division 2/Subdivision I, Personal Protective Equipment 

    Division 2/Subdivision J, General Environmental Controls (Lockout/Tagout)

    Division 2/Subdivision N, Material Handling and Storage

    Division 2/Subdivision O, Machinery and Machine Guarding 

    Division 2/Subdivision P, Hand and Portable Powered Tools

    Division 2/Subdivision R, Special Industries (sawmills, pulp and paper mills, etc.)

    Oregon OSHA Program Directive A-280, National Emphasis Program on Amputations

    Construction

    Division 3/Subdivision E, Personal Protective and Life Saving Equipment 

    Division 3/Subdivision I, Tools — Hand and Power 

    Agriculture

    Division 4/Subdivision I, Protective Equipment  Division 4/Subdivision J, Work Environment (Lockout/Tagout)

    Division 4/Subdivision N, Material Handling 

    Division 4/Subdivision O, Equipment Guarding 

    Division 4/Subdivision P, Small Tools

    Forest Activities

    Division 7/Subdivision D, Personal Protective Equipment and Programs

    Division 7/Subdivision H, Machines Used in Forest Activities 

    Source: Wisconsin Department of Workforce Development.

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    Abrasive wheel grinder Abrasive wheels and grinding machinescome in many styles, sizes, and designs.Both bench-style and pedestal (stand)grinders are commonly found in manyindustries. These grinders often have eithertwo abrasive wheels or one abrasive wheeland one special-purpose wheel such as a wirebrush, bufng wheel, or sandstone wheel.

    These types of grinders normally come with themanufacturer’s safety guard covering most ofthe wheel, including the spindle end, nut, andange projection. These guards must be strongenough to withstand the effects of a burstingwheel. In addition, a work rest and transparentshields are often provided.

    Hazard

    Bench-style and pedestal grinders createspecial safety problems due to the potential ofthe abrasive wheel shattering; exposed rotatingwheel, ange, and spindle end; and a naturallyoccurring nip point that is created by the workrest. This is in addition to such concerns asflying fragments, sparks, air contaminants, etc.Cutting, polishing, and wire buffing wheels cancreate many of the same hazards.

    Grinding machines are powerful and designedto operate at high speeds. If a grinding wheel

    shatters while in use, the fragments can travelat more than 300 miles per hour.

    In addition, the wheels found on these machines (abrasive, polishing, wire, etc.) often rotate atseveral thousand revolutions per minute. The potential for serious injury from shooting fragmentsand the rotating wheel assemblies (including the ange, spindle end, and nut) is great. To ensurethat grinding wheels are safely used in your workplace, know the hazards and how to control them.

    Solution Abrasive wheels used on bench and pedestal grinding machines must be equipped with safetyguards. The safety guard encloses most of the wheel – covering the ange, spindle end, andnut projection – while allowing maximum exposure of the wheel periphery. The exposure of

    the wheel should not exceed 90 degrees or one-fourth of the periphery (see diagram below).

    DEWALT Industrial Tool Co.

    Tool rest

    Exposed spindle end, ange, and nut.No tool/workrest.

    This exposurebegins at apoint notmore than65 degreesabove thehorizontalplane of thewheel spindle.

    Wherever thenature of thework requirescontact with thewheel below thehorizontal planeof the spindle,the exposuremust not exceed125 degrees.

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    Because the safety guard is designed to restrain the pieces of a shattered grinding wheel, thedistance between the safety guard and the top periphery of the wheel must not be more than¼ inch. If this distance is greater because of the decreased size of the abrasive wheel, thena “tongue guard” must be installed to protect workers from ying fragments in case of wheelbreakage. This “tongue guard” should be adjustable to maintain the maximum ¼ inch distancebetween it and the wheel.

     An adjustable work rest must also be installed and maintained at a maximum clearance of1/8 inch between it and the face of the wheel.

    In addition to offering a stable working position, this small clearance must be maintained toprevent the operator’s hands or the work from being jammed between the wheel and the rest,which may cause serious injury or the wheel to break.

     All abrasive wheels must be closely inspected and ring-tested before mounting to ensurethat they are free from cracks or other defects. Wheels should be suspended from the centermounting hole and tapped gently with a light, nonmetallic instrument. A stable and undamagedwheel will give a clear metallic tone or “ring.” If a wheel sounds dead or dull, it may be cracked.Do not use it. This is known as the “ring test.”

    The spindle speed of the machine must also be checked before mounting the wheel to becertain that it does not exceed the maximum operating speed marked on the wheel.

     Always follow the manufacturer’s recommendations.

    References

    General Industry

    Oregon OSHA Division 2/Subdivision O, 1910.215Construction

    Oregon OSHA Division 3/Subdivision I, 1926.300(b)(7) & 1926.303

    Agriculture

    Oregon OSHA Division 4/Subdivision O, OAR 437-004-2100

    American National Standards Institute

    ANSI B7.1 Safety Code for the Use, Care, and Protection of Abrasive Wheels

    ANSI B11.9 Safety Requirements for Grinding Machines

    • Proper exposure angle (90°)• Adjustable “tongue guards” (1⁄4”)• Adjustable tool/work rest (1⁄8”)

    Plastic glass (Plexiglas) shields are optional. They

    are not a substitute for eye and face protection andare not included as a part of the guard (unless theyare adjusted accordingly and have strength equal tothat of the safety guard).

    Tool rest

    Spindle guard

    Tongue guard

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    Worker’s Fatal Injury Leads to

    OSHA Citations, Penalties forMilwaukee Foundry

    Company Faces $156,500 Fine

    for Safety Shortcomings

    MILWAUKEE, WI – Fatal injuries sustained by a foundry workerat Grede Foundries, Inc., Milwaukee Steel Foundry, Milwaukee,might have been avoided if safety procedures for abrasive grindingmachinery had been followed, according to the Occupational Safety

    and Health Administration of the U.S. Department of Labor. OSHAproposed a $156,500 ne.

    “Protecting the health and safety of workers in America is a chief goalof the U.S. Department of Labor,” said U.S. Secretary of Labor ElaineL. Chao. “OSHA’s standards prescribe excellent methods to keepworkers safe from the hazards associated with grinding wheels, andwe will make certain standards are followed.”

    OSHA’s Milwaukee area ofce director, George Yoksas, said theagency opened an inspection of the foundry following the Jan. 7,2003, accident that occurred when an abrasive wheel on a standgrinder exploded, propelling fragments that struck the grinder

    operator. The wheel guard was unable to contain the fragments fromthe 30-by-2-inch abrasive wheel.

     As a result of that investigation, OSHA proposed willful and seriouscitations alleging the lack of a preventative maintenance program,failure to ensure the grinder was running at an appropriate speedwithin the grinding wheel tolerance, and issues involving machineguarding and other adjustments to the machine.

    Source: Federal OSHA Regional News Release, July 7, 2003

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    Horizontal band saw A horizontal band saw uses a thin,exible, continuous metal bandwith cutting teeth on one edge.Horizontal band saws are usedprimarily for cutting metal stock,such as angle iron and other

    round and at stock. The bladeruns horizontally on two pulleysthrough two separate guides.

    The operator secures the stockon the table and manuallyassists the saw as it cuts.

    HazardSerious cuts or amputations canoccur if the operator contacts the blade.Extreme caution is necessary because the

    operator’s hands may come close to thesaw blade, and the entire run of the bladecannot be fully guarded.

    SolutionGuard the entire blade, except at the point ofoperation (the working portion of the bladebetween the two guides). Band saw wheelsmust be fully encased.

    Make sure the saw includes a tension-controldevice to indicate proper blade tension.

    References

    General Industry

    Oregon OSHA Division 2/Subdivision O,1910.212 – General Requirements for AllMachines

    American National Standards Institute

    ANSI B11.10 – Metal Sawing Machines

    RL Johnson Co.

    Horizontal band saw blade guard.

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    Vertical band saw A vertical band saw uses a thin, exible,continuous metal band with cutting teethon one edge. It is a versatile saw usedto cut both wood and metal stock andalso to cut and trim meat. The bladeruns on two pulleys, driver and idler, andthrough a work table where material isfed manually.

    In order to cut, the operator is requiredto hand-feed and manipulate the stockagainst the blade. The operator must alsokeep the stock at on the work table andexert the proper amount of force.

    HazardSerious cuts or amputations can occur ifthe operator contacts the blade. Extreme

    caution is necessary because theoperator’s hands may come close to thesaw blade and a band saw cannot be fully guarded.

    SolutionGuard the entire blade except at the point ofoperation (the working portion of the bladebetween the bottom of the sliding guide rollsand the table).

    Use an adjustable guard for the portion of theblade above the sliding guide rolls so that it

    raises and lowers with the guide. Properlyadjust the blade guide to t the thicknessof the stock and ensure the guard is asclose as possible to the stock.

    Bandsaw wheels must be fully enclosed.

    References

    General Industry

    Oregon OSHA Division 2/Subdivision O,1910.213(i)

    Agriculture

    Oregon OSHA Division 4/Subdivision O,OAR 437-004-2000(4)

    American National Standards Institute

    ANSI 01.1 Woodworking Machinery –Safety Requirements

    ANSI B11.10 Metal Sawing Machines

    Large portion of exposed blade at point ofoperation.

    University of British Columbia

    Vertical band saw

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    CNC turning machineComputer numericallycontrolled (CNC) machiningcenters cut and shape anassortment of precisionproducts from automobileparts to general machineparts. Operating in eitherhorizontal or verticalpositions, CNC machineryincludes machining toolssuch as lathes, multi-axis spindles, and millingand boring machines; thefunctions formerly performedby human operators areperformed by a computer-control module. CNCmachinery is either hand

    loaded or automatically fed.Most CNC machinery is partially or totally enclosed by metal enclosuresequipped with thermoplastic vision panels, most commonly polycarbonate.

    HazardTwo primary hazards arise from CNC turning operations: Entanglement and the ejection ofparts. Serious lacerations, fractures, amputations, or even death can occur if an operatorcontacts or becomes entangled in or between the tooling or rotating work piece. Similar injuriesor death can also occur from being struck by ejected parts (e.g., cutters or other tools, chucks,or the work piece).

     Although the risk of injury from ejected parts is lessened due to the interlocked enclosure ofCNC machinery, recent research has shown that polycarbonate materials used in the unit’svision panels can degrade after exposure to the metalworking uids and lubricants used in themachining process.

    Over time, vision panels may not be able to contain ejected parts. Most ejections at CNCturning machines are caused by a setup error or failing to properly maintain work-holdingdevices.

    Unexpected movement or startup caused by faults in the control system can also causeserious injury.

    SolutionTo prevent access into the point-of-operation area, ensure the CNC machine is fully enclosedand equipped with an interlocked guard (door). The cutting tools should not start unless thedoor is in a closed position and should stop when the door is opened. Many machines lock theguard in position during operation and can only be opened when the tooling stops. If accessinto the point of operation is infrequent, install a xed enclosure that can be removed only formaintenance activities.

    CNC control panel

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     Automatic loading and unloading methods and automatic tool changing further reduce theexposure to the point of operation.

    To prevent injury from ejected parts, make sure the polycarbonate vision panels are strongenough to contain ejected parts. Also, verify the appropriate rotational speed for the particularwork piece and inspect the chuck jaw assemblies, work piece clamps, and all component parts

    of the turning xtures.

    References

    General Industry

    Oregon OSHA Division 2/Subdivision O, 1910.212  – General Requirements for All Machines

    HSE Engineering Information Sheet #33 “CNC turning machines: Controlling risksfrom ejected parts”

    ANSI B11.22 Safety Requirements for Turning Center and Automatic NumericallyControlled Turning Machines

    ANSI B11.23 Safety Requirements for Machining Centers and AutomaticNumerically Controlled Milling, Drilling, and Boring Machines

    OSHA Safety Hazard Information Bulletin 00-06-23 “Potential Hazards Associatedwith the Use of Replacement Materials for Machine Guarding ” (June 23, 2000)

    Determine if the polycarbonate vision panels are strong enough tocontain ejected parts.

    CNC turning machine – continued

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    HAZARD ALERT 

    Oregon OSHA

    www.orosha.org800-922-2689

    Hazard alerts provide information on unusual safety or health hazards or unusual or hazardous materialsor practices. For more information contact the Oregon OSHA Standard and Technical Resources Sectionat 503-378-3272, toll-free at 800-922-2689, or visit our website at www.orosha.org.

    OR-OSHA 2993 (3/15)

    CNC Lathe Safety

     What happened?

     A machinist died when he was struck by a 40-pound pump rotor he was turning in a vertical CNCmetal lathe. The rotor was a different size than others he had worked on and the chuck jaws were not

     properly extended to secure it. While he was standing in front of the machine’s Lexan viewing window,the rotor suddenly dislodged from the chuck jaws, broke through the window, and struck him in chest.The force of the blow knocked him back 27 feet off the work platform and onto a concrete floor.

    Lexan

    window

    2    7      F     e   e   t     

    How to prevent similar injuries

    Ensure that the parts being machined are the appropriate size sothat they engage properly with the chuck and the cutting tool.

    Remember 

    Lexan windows are not guards. Do not rely on them to protect youif a part ejects from the chuck.

    For more information:

    • CNC Turning Machines: Controlling Risks from Ejected Parts(HSE Engineering Information Sheet #33)

    • Potential Hazards Associated with the Use of Replacement Materials for

    Machine Guarding (OSHA Hazard Information Bulletin 00-06-23)

    Photo of the accident site: The CNC lathe is in the upper left.

    http://www.hse.gov.uk/pubns/eis33.pdfhttps://www.osha.gov/dts/hib/hib_data/hib20000623.pdfhttps://www.osha.gov/dts/hib/hib_data/hib20000623.pdfhttps://www.osha.gov/dts/hib/hib_data/hib20000623.pdfhttp://www.hse.gov.uk/pubns/eis33.pdf

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    Compacting and baling equipmentCompacting and baling equipment reduces large amountsof solid waste to smaller, more manageable units by meansof powered rams. In general, compactors compress refuseinto containers for transport. Baling equipment is designedto compress material (e.g., cardboard boxes) and produce abale (bound or unbound) that is handled as a unit.

     A wide range of hazards exist simply due to the size,conguration, and operation of compactors and balers. Somemachines allow direct access to the compression chamber,while others have a hopper or chute through which materialfeeds into the machine. Machines may operate in a manual,semiautomatic, or automatic mode. The rams may movevertically or horizontally.

    HazardWorkers can be crushed by the ram motion if guarding is missing or bypassed, or if lockoutprocedures are not followed during maintenance activities. Older compacting equipment may

    not have appropriate interlock guarding or may not have enough guarding to enclose thechamber or point-of-operation area completely.

    Severe injury and death can also occur during service or maintenance tasks on or insidean energized or jammed machine if the machine cycles automatically or if the machine isactivated by another worker who is unaware that someone is inside the chamber. Becauseram motion stops during a jam, workers may not recognize that the machine remains energizedand that the ram could activate unexpectedly. Similarly, if conveyors are used to feed materialinto a compactor or baler, workers may mistakenly believe that shutting down the conveyoralso prevents the compactor or baler from operating.

    In addition to the hazardous-energy potential, working inside these machines may also presentconned-space hazards such as hazardous atmospheres and engulfment.

    Solution Access covers and point-of-operation guarding must be interlocked in such a manner thatthe compactor cannot be operated if the guard or loading door is removed or opened. Mostcompactors and balers today prevent workers from reaching into the point of operation byconguration, cycling controls, and interlock guarding that interrupt or reverse the ram’smotion if the compression chamber doors are opened. However, older equipment may nothave these features and it would be wise to consult with the manufacturer for possibleretrots or upgrades.

    Whenever unjamming, adjusting, cleaning, repairing, or performing other maintenance tasks,the machine must be isolated from all its energy sources and “locked out.” If conveyors areused, they should be interconnected so that a single, lockable device can de-energize andisolate the power to both machines. Lockout procedures are further explained on Page 58.

    Follow permit-required conned space entry procedures whenever working inside thesemachines.

     Also, refer to Oregon OSHA’s rules for Stationary Compactors, Self-Contained Compactors,and Balers for specic control, marking, and signage requirements.

    Pacic Compactor Corporation

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    References

    General Industry

    Oregon OSHA Division 2/Subdivision O, OAR 437-002-0256 — Stationary Compactors,Self-Contained Compactors, and Balers

    Oregon OSHA Division 2/Subdivision J, 1910.147 — The Control of Hazardous Energy(Lockout/Tagout)

    Oregon OSHA Division 2/Subdivision J, 437-002-0146 — Conned Spaces

    ANSI Z245.2 Stationary Compactors — Safety Requirements

    ANSI Z245.5 Baling Equipment — Safety Requirements

    NIOSH Publication No. 2003-124 Preventing Deaths and Injuries While Compacting orBaling Refuse Material 

    Sixteen-year-old produce-market workerdies from crushing injuries

    Caught in a vertical downstroke baler 

     A 16-year-old male produce-market worker died from crushing injuries after beingcaught in the vertical downstroke baling machine that he was operating. The victim,working alone in the basement of a small produce market, was crushing cardboardboxes when at some point in the compacting process he was caught by the machine’shydraulic ram. The victim was discovered by an exterminator spraying the basement,who told the store manager to call police and emergency medical services (EMS).

    Subsequent examination by investigators revealed that the safety interlock had beenbypassed, allowing the machine to operate with the loading door in the open position.The victim may have reached into the baling chamber during a compression cycle toadjust a tie wire or a liner box and was caught by the ram platen.

    NIOSH investigators concluded that, to help prevent similar incidents, employers should:

    • Ensure that all safety devices on baling machines are functioning correctly andenforce proper operation.

    • Ensure that employees, including management personnel, know and understandthe importance of the machine’s safety features.

    • Comply with child labor laws that prohibit youths under the age of 18 from operatingor assisting in operation of paper balers.

    • Develop and implement a comprehensive employee safety program that includestraining in the safe operation of machinery and the importance of the machine’ssafety devices.

    Source: NIOSH FACE Report 2000

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    Miter saw, unguarded

    Cut-off saws Although there are many specic types of cut-off saws, they are all circular saws designedto cross-cut stock at exact lengths and angles. The following are some of the common cut-offsaws used today.

    Miter saw A miter saw is a versatile circular power saw mounted on a

    hinged frame and designed to make accurate angle cuts.When the blade is lowered in a chopping motion, the bladecuts through the work piece, passing through a slot in the base.

    Chop saw  A chop saw is a lightweight circular saw mounted on a spring-loaded pivoting arm and supported by a metal base. Theoperator clamps the stock to the fence, pulls the blade throughthe work piece, and guides the saw back to its upright position.Chop saws typically do not have the cutting capacity of mitersaws.

    Swing sawSwing saws, both overhead and inverted, are swung froma pivot, either above or below the saw arbor. The operatorpositions the stock, pulls the saw across to make the cut, andthen returns the saw to its original position.

    Jump saw Similar to an inverted swing saw, a jump saw is a circular sawlocated underneath the stock and hold down (clamp) and isattached on an arm that pivots from behindthe saw arbor at approximately the sameheight. After the stock is positioned, the bladecomes up, cuts the stock, and drops belowthe table surface.

    These “undertable” saws are normallyoperated by a knee or foot pedal.

    HazardSevere cuts to or amputations of the ngersor hands can occur if they come in contact

    with the saw blade. If the rotating blade isnot properly guarded, exposure can occurduring operation or when the saw is idling.

    Overhead swing saws can pose additionalhazards if the return device fails, if the sawbounces forward from a retracted position,or if the saw blade is able to go past theedge of the table, possibly contacting theoperator’s body.

     Although not as common as with ripsaws, hazardous kickbacks might also occur.

    DEWALT Industrial Tool Inc.

    Miter saw

    DEWALT Industrial Tool Inc.

    Chop saw

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    Overhead swing saw missing a lower bladeguard and extending beyond table edge.

    Missing “nose guard” on a jump saw.

    SolutionOvertable cut-off saws (miter, chop, and overheadswing saws) must be provided with xed hood guardsthat enclose the arbor and top half of the saw. Thesesaws also must be equipped with a self-adjustinglower blade guard that automatically adjusts itself tothe thickness of the material being cut and providescontinuous protection from the blade. Most guardssupplied by manufacturers are designed to move outof the way as the blade nears the cut. If a guard seemsslow to return to its normal position, adjust or repair itimmediately.

    Overhead swing saws must be provided with a device(i.e., counterweight) to return the saw automatically to theback of the table when released at any point of its travel.Limit chains must also be provided to keep the saw fromswinging beyond the front or back edges of the table.

    Inverted (undertable) swing saws and jump saws,when idling, are guarded by their enclosure.

    During operation, a hood-type guard or clamping meansmust be provided for the blade portion that protrudesabove the table or above the stock being cut in additionto holding down the stock.

    These saws must have a “nose guard” afxed to thesaw table in front of the hood guard (or another methodproviding equivalent protection) to prevent accidentalentry of ngers or hands into the path of the saw bladefrom the front (Oregon OSHA Hazard Alert, “Nose

    Guards,” applicable for cut-off, inverted swing cut-off,and similar saws).

    References

    General Industry

    Oregon OSHA Division 2/Subdivision O,1910.213(g) – Swing saw

    Oregon OSHA Division 2/Subdivision O,1910.213(h)(1) – Miter/chop saw 

    Construction Oregon OSHA Division 3/Subdivision I,

    1926.304(g)(1) – Miter/chop saw 

    Agriculture

    Oregon OSHA Division 4/Subdivision O,OAR 437-004-2000(5)

    American National Standards Institute

    ANSI O1.1 – Woodworking Machinery – Safety Requirements

    Properly guarded jump saw.

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    Drill pressThe drill press is a versatile machinethat uses a multiple-cutting-edged drillbit secured in a rotating chuck to boreand drill holes, normally into wood stock.Either in oor or bench-top designs, drillpresses are usually arranged vertically,requiring the operator to raise andlower an operating handle in order tocontrol the drill bit. These machines alsohave variable speeds and some havemultiple spindles for gang drilling. Themost commonly used drill press is asingle-spindle, oor-mounted, belt-drivenmachine for non-production drilling.

    HazardSerious lacerations and entanglementcan occur if operators contact therotating bit or chuck, or when operatorstry to hold the stock by hand whendrilling. If not adequately secured, thestock can spin violently and contact theoperator and others nearby. Also, injuriescan occur from a projected chuck keyif it is left in the chuck.

    SolutionUse jigs or xtures to fasten the stockto the bed and stabilize the work piece.

    This allows the stock to be secured fordrilling and the operator’s free hand to be positioned away from the rotating chuck anddrill bit. The drill bit is more likely to grab and twist an unstable work piece.

    In many repetitive drilling applications, specially designed guards or shields are installed toprotect the operator from the potential exposure to rotating drill chucks and drill bits. A xeduniversal-type shield can be used on larger gang drills.

    References

    General Industry

    Oregon OSHA Division 2/Subdivision O, 1910.213(l)

    ANSI 01.1 – Woodworking Machinery – Safety Requirements

    ANSI B11.8 – Drilling Milling, and Boring Machines

    Vertical drill press with vise (to prevent stock from spinning).

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    Ironworker

    Scotchman Industries, Inc

    “Strippers” are designed to holdthe material down and may also providesome protection from the punch hazard.

    Ironworkers are versatile, multi-station metalfabricating machines that offer component toolingoptions to perform punching, shearing, notching-coping, and, sometimes, bending operations. Theworkstations can work singly or simultaneouslyand all tooling moves vertically.

    Ironworkers are normally powered hydraulically.

    HazardSevere crushing injuries or amputations can occurif an operator makes contact with any of the pinchor shear points this machine provides.

    Flying or ejected parts from either the stock orthe tooling can strike operators and other workersin the area. Punches are hardened and will notbend as they collide with dies. If a punch is out

    of alignment, it is more likely to ake or evenexplode, causing serious harm to the operator.

    Unprotected foot pedals can also introduce thepossibility of accidental cycling.

    SolutionGuard all pinch and shear points with xed oradjustable guarding. Guards should be adjusteddown to within ¼ inch from the top of the material tothe bottom of the guard (or stripper when punching).Most newer machines are equipped with adjustable

    restrictors that surround the material in-going areasand should allow just enough clearance for thematerial to enter.

    Beware of machines with automatic urethane hold-downs. These hold-downs, if not adjusted properly,also come down with many tons of force and can behazardous pinch points.

    Ensure proper alignment of the punch and dies.Cover foot pedals to prevent accidental cycling.

    ReferencesGeneral Industry

    Oregon OSHA Division 2/Subdivision O,1910.212 — General Requirements for All Machines

    ANSI B11.5 Safety Requirements for theConstruction, Care, and Use of Iron Workers

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    Jointer Jointers face and straightenwood and are used primarilyto square edges. The operatorpasses stock over a cylindrical,multiple-knife cutting headwhile keeping the stock ushagainst a guide.

    HazardSevere lacerations oramputations can occur ifthe operator’s hands andngers come in contact withthe knives. This can happenwhen operating an unguardedmachine, jointing narrowlengths of stock when notusing a jig or other holdingdevice, or when the operator’sngers ride along the surfaceof the jointer and through theself-adjusting guard whilefeeding the wood. Also, stockmay kick back and expose theoperator’s hands to the cutter head.

    Solution A spring-loaded, self-adjusting guard mustbe provided to enclose the horizontal cutting

    head when stock is not being fed. The guardautomatically adjusts to cover the unusedportion of the head and remains in contact withthe stock at all times. A guard must also coverthe section of cutting head behind the fence(gage). For vertical-head jointers, completelyenclose the cutter head except for the slot toapply the stock. This guard can be part of thelocal exhaust system.

    The knife projection on the cutting head must not be more than 1/8 inch beyond the cylindricalbody of the head. The clearance between the edge of the rear table (infeed) and the cutting

    head must not exceed 1/8 inch. The opening in the table must be kept as small as possible.Hold-down push shoes and sticks are recommended when using the jointer.

    References Oregon OSHA Division 2/Subdivision O, 1910.213(j)

    ANSI 01.1 – Woodworking Machinery – Safety Requirements

    Unique Projects

    Photo: University of UtahJointer 

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    Metal lathe A metal lathe is a precision turning machine that rotatesa metal rod or irregular-shaped material while a tool cutsinto the material at a preset position. Similar to the woodlathe, the metal lathe normally consists of a headstockand base that houses one or more spindles on whicha work-holding device (chuck) can drive the stock andthe cutting tools can remove metal, producing mainlycylindrical and conical shapes.

    There are basically two main types of metal lathes:Lathes for shaft work (material supported at two ormore locations) and lathes for bar (bar stock introducedthrough the spindle) or chucking work (individual piecessecured at the chuck). Shaft lathes include enginelathes, vertical-shaft lathes, and turning centers. Barand chucking lathes include turret lathes (vertical andhorizontal) and vertical boring mills.

    HazardSevere injuries and death can occur primarily from beingcaught in or struck by rotating parts. An operator can bepulled into the lathe from working perilously close (e.g.,polishing a slotted shaft with emery cloth) or wearinggloves, loose clothing, loose hair, jewelry, etc. Trappingspaces are also created between the cutting tool, itsmounting, and the work piece or chuck.

    Projected parts or material such as chuck keys orunsecured work pieces can also strike nearby operators.

    Flying chips and coolant also present hazards to the operator.

    Solution Avoid wearing gloves, loose clothing, long hair, jewelry, or other dangling objects near latheoperations. Pay close attention to work pieces thathave keyway slots or other surface proles that mayincrease the risk of entanglement. Assess the need tomanually polish (e.g., emery cloth) rotating material. Ifnecessary, consider milling keyways or other prolesafter polishing or use emery cloth with the aid of atool or backing boards. Always use a brush or tool to

    remove chips.Cover work-holding devices (chucks)and tool trapping space hazards(especially in automatic or semiautomaticmodes) with secured xed or movableguards or shields. Vertical lathes andcontrolled turning centers are normallyprovided with xed or interlockedguarding that prevents access during theautomatic cycle.

    RDM Industrial Services Ltd

    Hazardous exposures are present simply dueto the operator’s close proximity to the lathe’srotating parts.

    Fabricated quill-mounted guard to enclose cathead.

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    Make sure all work pieces and work-holding devicesare secure and free from defects. Remove the chuckkey from the chuck after securing the material. Agood rule is to never take your hand off the chuckkey until you set it back onto a table. Consider usinga spring-loaded wrench.

    Provide a chip/coolant shield unless another guardor shield already provides protection. This does notreplace the need for eye and face protection, however.

    NOTE: Guards or shields used to protect latheoperators from projected parts must either be from themanufacturer or, if fabricated in-house, meet or exceedthe same impact-resistance specications as the originalmanufactured part. Various materials (such as polycarbonates)may possess different and less-effective impact-resistance characteristicsthan the original materials used by the manufacturer.

    In one case, an operator was killed when the bell casting on a lathe came loose while the lathewas turning and was propelled through two, ½-inch-thick Plexiglas windows. The Plexiglas wasinstalled as a replacement for the manufacturer’s original composite window on the machine’sdoor frame. The operator was fatally struck in the head and neck as he was looking throughthe window.

    The manufacturer’s original observation window was made of a ¼-inch-thick laminated glass plate with a ½-inch-thick polycarbonate window, separated by an approximately ¼ inch airspace. The original window was replaced with Plexiglas material that had a lower impactresistance than the polycarbonate shield originally supplied by the machine manufacturer.

    Polycarbonates are a family of various polymers that includes Macrolux, Lexan, Relex, Replex,Dynaglass, Exolite, Verolite, Cyrolon, and Makrolon. These materials have different impact-

    resistance characteristics for different thicknesses and surface areas. It is important to note thatincreasing the thickness beyond a certain level does not always improve or increase the impactresistance. Some studies have shown polycarbonate degrades due to age and prolongedcontact with metalworking uids and lubricants.

    References

    General Industry

    Oregon OSHA Division 2/Subdivision O, 1910.212— General Requirements for All Machines

    Oregon OSHA Program Directive A-236 – Guarding: Metal Lathe Chucks (Engine Lathes) 

    OSHA Safety Hazard Information Bulletin 00-06-23 – Potential Hazards Associated withthe Use of Replacement Materials for Machine Guarding  (June 23, 2000)

    HSE Engineering Information Sheet #33 – CNC turning machines: Controlling risks from ejected parts

    HSE Engineering Information Sheet #2 – Accidents at metalworking lathes using emery cloth

    ANSI B11.6 – Lathes – Safety Requirements for Construction, Care, and Use

    Chipmakers Metalworking World 

    Metal lathe – continued

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    Wood lathe

    Delta Inc.

    While most tools rotate or move a blade or bit to cut,the wood lathe moves the work piece being cut. Thewood lathe is used to turn stock into round objects bysecuring the stock between two centers: the headstockand tailstock (spindle turning), or by securing the workto the headstock only with a faceplate (facing). Spindle

    turning is used for long objects such as table and chairlegs, while facing is used for cups, bowls, and plates.

    The stock rotates rapidly while the operator applies asingle-point tool to the wood. The operator holds thetool on a tool rest and advances it along the length ofthe tool rest to shape the stock as desired.

    HazardDue to its unique operation of rotating the stock beingcut, the lathe presents several concerns. The primary hazards

    arise when using a hand tool against the rotating stock and theclose proximity of the operator to the rotating parts.

    Serious injuries can occur if the tool becomes caught between therest and the rotating stock, bringing the operator’s hands in with it. Also, hands, arms, clothing, hair, or jewelry may be caught on therotating parts and pulled into the machine simply because of theclose distance the operator is from the machine’s components.

    Projected or broken work pieces can be another hazard if notsecured between the centers or if the work piece is defective.Furthermore, chuck keys can eject if left in the chuck. Flyingwood chips from the turning operation also can pose a hazard on

    wood lathes.

    SolutionCover all rotating parts and points of operation withshields.

    Cover lathes used for turning long stock with long,curved guards that extend over the top of thelathe. These shields, or guards, must protect theoperator if the stock comes loose and is thrownfrom the machine.

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    Make sure the tool rest is secure and set close to thestock (1/8 inch). Rotate the stock by hand to make sure itclears the tool rest before turning the lathe on. Guide theturning tool on the rest only — do not attempt to support

    the tool with your hands.

    The work piece must be secured and should be free ofcracks, splits, knots, and other defects. Check for weakglue joints.

    Remove chuck keys or adjusting wrenches. Develop thehabit of never letting go of the chuck key or wrench whenyou are using it. Consider using a spring-loaded chuckwrench.

    Check to make sure that the chuck is secured beforeturning the lathe on.

    Never permit operators to wear loose clothing, long hair, jewelry, dangling objects, or gloves.

    References

    General Industry

    Oregon OSHA Division 2/Subdivision O, 1910.213(o)

    ANSI 01.1 Woodworking Machinery – Safety Requirements

    Make sure the tool rest is secure and setclose to the stock.

    Wood lathe – continued

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    Milling machine A milling machine removes material from a workpiece by rotating a cutting tool (cutter) and moving itinto the work piece. Milling machines, either verticalor horizontal, are usually used to machine at andirregularly shaped surfaces and can be used to drill,bore, and cut gears, threads, and slots.

    The vertical mill, or “column and knee” mill, is themost common milling machine found in machineshops today. The general construction of this millincludes the quill, which moves vertically in the headand contains the spindle and cutting tools. The kneemoves up and down by sliding parallel to the column.The column holds the turret, which allows the millinghead to be positioned anywhere above the table.Hand wheels move the work table to the left and right (X axis),in and out (Y axis), in addition to moving the knee, saddle,and worktable up and down (Z axis).

    HazardSerious injuries and entanglement can occur if the operatorcontacts the rotating cutter. Metal shavings and lubricating/cooling uids might also present a risk from the point ofoperation area.

    Material might spin and strike an operator if the material is notsecured to the table. Injuries can also occur from a projectedwrench if it is left in the spindle.

    SolutionSecure the work piece, either by clamping it ontothe work table or by clamping it securely in a visethat is clamped tightly to the table.

    NOTE: Computer numerical controlled (CNC) millsare rapidly replacing manually fed machines, mainlyfor versatility and production reasons. The increasedautomation does not normally require the operator tomove the hand wheels (like the traditional machines),so operators must always keep their hands away fromthe point of operation. A guard or shield that enclosesthe cutter head or milling bed may be considered to protect the operator from the cutting area, ying metal

    shavings, and lubricating or cooling uids.

    Make sure the tightening wrench is removedfrom the mill.

    References

    General Industry

    Oregon OSHA Division 2/Subdivision O, 1910.212 – General Requirements for All Machines

    ANSI B11.8 Drilling, Milling, and Boring Machines

    Ball State Universit

    In some cases, a shield can provide an operatorprotection from the cutter, as well as from metalshavings and metal working uids.

    Vertical “column and knee” mill.Illinois Institute of Technolog

    Georgia Tech Research Institut

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    Planer Planers are most frequently used to producesmooth faces on boards and to mill them toparticular thicknesses. Planers are differentfrom jointers because of their capacity toplane wider surfaces and the capability tocontrol thickness.

    Planers have automatic feed systems thatpull the work through the horizontally rotatingblades and out the back.

    HazardSevere lacerations, amputations, or avulsions(tearing away) can occur if the operator’shand or arm is fed through the machine andcontacts the cutting heads.

    Serious injury can also occur from kickback. A kickback can occur when lowering the tablewith the power on and the stock still in themachine, feeding stacked boards, or planingboards shorter than the manufacturer’s recommendation.

    SolutionKeep the machine guards in place at all times.

    Keep your hands out of the machine feeding area and allow the planer topull the stock through.

    Never lower the table duringoperation and never feed stacked

    boards. Also, follow manufacturer’srecommendations for allowablematerial dimensions.

    Keep your body to the sideof the stock.

    References

    General Industry

    Oregon OSHA Division 2/Subdivision O, 1910.213(n)

    ANSI 01.1 Woodworking Machinery – Safety Requirements

    Cornell University 

    DEWALT industrial Tool Co.

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    Plastic injection molding machinery

    Plastic injection molding machinesproduce plastic parts by convertingplastic pellets into molten material,injecting the molten plastic into a mold,and cooling the plastic material.One half of the mold is connected to a

    movable platen (clamp) and the otheris connected to a stationary platen. As the machine prepares to injectmolten plastic into the mold, the platensclose and press the mold halvestightly together. When the plastic iscooled, the movable platen retracts, andthe solidied plastic parts are removed.

    HazardCrushing injuries, avulsions, and amputations can result from the numerous moving parts and

    pinch points. Severe burns can also occur from the hot temperatures. Such injuries can resultfrom safeguards that are missing, improperly installed, removed, or bypassed.

    SolutionSince these machines are complex piecesof equipment, well-designed and effectiveguarding is a must. An interlocked movablebarrier (operator’s door or “gate”) shouldbe installed to block operator accessto moving parts while the machine is innormal production. The safety interlocks

    (mechanical, electrical, hydraulic) preventthe mold from closing when the door isopen. Install guarding if a person can reachover the machine into the mold area.

    References

    General Industry

    Oregon OSHA Division 2/Subdivision O 1910.212 – General Requirements for All Machines

    ANSI/SPI B151.1 Safety Requirements for Horizontal Injection Molding Machines

    ANSI/SPI B151.27 Safety Requirements for the Integration of Robots with Injection MoldingMachines 

    OSHA Machine Guarding eTool – Plastics Machinery

    SPI/OSHA Alliance

    OSHA Alliance Program Products: www.osha.gov 

    Worker Health and Safety Resources: www.plasticsindustry.org 

    IRSST Publication – Horizontal Plastic Injection Molding Machine - Safety Checklists

    OSHA SPI Allianc

    OSHA

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    Portable abrasive grinder One of the most common portable tools foundin virtually any shop, the portable grinder isincredibly useful for grinding and nishingmaterial of all shapes and sizes.

    Hazard

    The hazards associated with portable grindersare similar to those of pedestal or benchgrinders. First of all, serious abrasion orcuts can occur from contacting the rotatingabrasive stone. There is also the potential forthe abrasive stone to shatter, plus the dangersof exposure to the rotating wheel, ange,and spindle end from kickback. Finally, otherconcerns, such as ying fragments and sparks,are present during portable grinding operations.

    SolutionThese types of grinders normally come with the manufacturer’s safety guard covering mostof the wheel. Abrasive grinder exposure must not exceed a maximum angle of 180 degreesand the top half of the wheel must be enclosed at all times. The guard must be mounted so itmaintains proper alignment with the wheel.

    Vertical “right angle” grinders must have a 180-degree guard between the operator and wheel.The guard must be adjusted so that pieces of a broken wheel will be deected away from theoperator. The above picture depicts a properly guarded “right angle” grinder.

    Cup wheel grinders must be guarded as described above or be provided with special “revolvingcup guards,” which mount behind the wheel and turn with it.

    There are exceptions for guarding based on work practices and for other grinders [OregonOSHA Division 2/Subdivision P, 1910.243(c)(1)]. Natural sandstone wheels and metal, wooden,cloth, or paper discs that have a layer of abrasive on the surface are not covered by OregonOSHA’s portable abrasive grinder rule.

     All abrasive wheels must be closely inspected and “ring-tested” before mounting to ensurethat they are free from cracks or other defects. The spindle speed of the machine also mustbe checked before mounting the wheel to be certain that it does not exceed the maximumoperating speed marked on the wheel. Always follow the manufacturer’s recommendations.

    ReferencesGeneral Industry

    Oregon OSHA Division 2/Subdivision P, 1910.243(c)Construction Oregon OSHA Division 3/Subdivision I, 1926.303

    Agriculture Oregon OSHA Division 4/Subdivision P, OAR 437-004-2230(3)

    American National Standards Institute ANSI/UL 45 – Portable Electric Tools

    ANSI B7.1 – Safety Code for the Use, Care, and Protection of Abrasive Wheels

    ANSI B11.9 – Safety Requirements for Grinding Machines

    DEWALT Industrial Tool Co.

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    Portable belt sander The portable belt sander is a general-purposenishing tool. The belt is looped around two ormore pulleys. The belt sander’s linear motionmakes it an excellent tool for sanding with thegrain of the wood.

    HazardSerious abrasion can occur from contacting themoving belt.

    In-running nip points – created where the beltmeets the pulley – can be present on the sideof the tool. Nip points allow ngers, clothing, orhair to become caught in the tool.

    SolutionBoth hands should be used to operate the portablebelt sander, one on the trigger switch and the otheron the front handle.

    Guard the unused runs of the sanding belt and allin-running nip points. This is normally accomplishedby the tool’s casing, enclosing the top portion ofthe belt and much of the side. The enclosure, orguard, on the sides must prevent the operator fromcontacting the nip points.

    References

    General Industry

    Oregon OSHA Division 2/Subdivision P,1910.243(a)(3)

    Agriculture

    Oregon OSHA Division 4/Subdivision P,OAR 437-004-2230(1)(d)

    DEWALT Industrial Tool Co

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    Portable circular sawThe portable circular saw is probablythe most commonly used power saw.Circular saws are versatileand used to crosscut, rip,and bevel cut.

    The operator adjusts the saw to

    the proper cutting depth andpushes the tool through the wood.

    HazardSevere cuts and amputations canoccur if the operator contacts thesaw blade. Many injuries occur whenthe lower portion of the blade is fullyexposed during operation or when the operator placeshis or her hand under the base plate (shoe) of the saw.

    Kickbacks can also present a signicant hazard.They occur when the saw blade binds in thecut and the saw kicks back toward the operator.Binding most often occurs when the piece beingcut off is not allowed to fall down, if cutting on anincline, or between two saw horses and eitherthe weight of the saw or the forward motioncauses the saw kerf (line of cut) to close.

    Solution All saws with a blade diameter greater than twoinches must be equipped with guards above

    and below the base plate (shoe). The upperguard must cover the saw to the depth of theteeth, except for the minimum arc required topermit the base to be tilted for bevel cuts. Thelower guard must enclose the teeth as much aspossible and cover the unused portion of theblade when cutting.

    When the tool is withdrawn from the work, the lowerguard must automatically and instantly return tothe covering position. Check that the retractinglower guard has returned to its starting position

    before laying down the saw. If the saw is setdown with the guard open, it usually spins in a tightcircle – sometimes cutting its own cord or possiblycontacting the worker’s foot.

    In addition, the lower guard must be equippedwith a lug or lever, located safely away from theblade teeth, that will permit the operator to shiftthe guard safely for starting unusual cuts. Neverhold or force the retracting lower guard in theopen position and never pin the guard up.

    DEWALT Industrial Tool Co.

    Never pin back the blade guard.

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    Kickbacks can be minimized by setting the proper blade depth so that the lowest tooth extendsno more than 1/8 inch beyond the bottom of the material. This limits the area of the bladein the kerf and also exposes less of the blade if the saw does kick back.

    It’s also important to keep the saw kerf open, reducing the chance for the saw to bind.The board being cut should be positioned so that the weight of the cutoff keeps the sawkerf open as the cut is being made. Also, make sure you are not cutting uphill – even the

    slightest incline can cause the saw to bind. The saw must always move in a straight line.If the blade wanders from its straight path, the rear of the blade can bind against the sideof the kerf. If the saw has to be turned off in the middle of a cut, make sure the blade hasstopped spinning before taking your hand off the saw. Always keep your body out ofthe line of potential kickback.

    Use two hands whenever possible, one on the trigger switch and the other on afront knob handle.

    Secure work being cut to avoid movement.

    References

    General Industry Oregon OSHA Division 2/Subdivision P, 1910.243(a)(1)(i)

    Oregon OSHA Division 2/Subdivision P, OAR 437-002-0266(1)

    Construction

    Oregon OSHA Division 3/Subdivision I, 1926.304(d)

    Agriculture

    Oregon OSHA Division 4/Subdivision P, OAR 437-004-2230(1)(a)

    American National Standards Institute

    ANSI/UL 45 – Portable Electric Tools

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    Portable jigsawHandheld jigsaws are useful for cutting intricatecurves and patterns in thin stock. They have thinblades that move rapidly up and down through thesaw’s guide plate. The blade is held in a chuck. Theoperator either holds the saw with one hand whilethe other hand is used to secure the stock, or thesaw is held with both hands if the stock is alreadysecured.

    HazardSerious cuts can occur when the operatorcontacts the reciprocating blade. Much of theblade is exposed by design and contact can bemade before or after the cut, or during the cutif the operator’s hand is securing the materialunderneath the stock and in the path of the blade.

    SolutionEnsure the portion of the blade above the guideplate is adequately guarded. This may requiresetting it to an appropriate height.

    Be aware of the portion of the blade below thestock, especially if you are using one hand tosecure the material.

    Make turns slowly and use a narrow blade forsharp turns.

    ReferencesGeneral Industry Oregon OSHA Division 2/Subdivision P,

    1910.243

    ANSI/UL 45 – Portable Electric Tools

    Construction

    Oregon OSHA Division 3/Subdivision I, 1926.300

    Agriculture

    Oregon OSHA Division 4/Subdivision P, 437-004-2230

    DEWALT Industr ial Tool Co.

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    Power pressPower presses are metalworking machines used primarily tocut, punch, or form metal using tooling (dies) attached to theslide (ram) and bed. The slide has a controlled reciprocatingmotion toward and away from the bed surface and at rightangles to it. It is guided in the frame of the machine – eithera “C” frame [open back inclined (OBI)] or straight side frame

     – to give a denite path of motion.

    The two most common types of power presses aremechanically and hydraulically powered. Though these twoshare common features, the mechanical power press hasbeen the most widely used throughout industry and hasbeen the subject of most of the research done, primarilydue to its tenure in industry and the number of injuriesassociated with it.

    The main components for power transmission on amechanical power press are the clutch, ywheel, andcrankshaft. The slide is attached to a crankshaft with

    connecting rods (“pitmans”) and the crankshaft is coupled tothe ywheel, which always rotates when the motor is running. A clutch is used to connect thespinning ywheel to the crankshaft. The crankshaft converts the rotary motion of the ywheel tothe downward and upward motions of the press slide.

    Two different types of clutches are used on mechanical power presses: full-revolution andpart-revolution clutches. Full revolution clutches, when tripped, cannot be disengaged untilthe crankshaft has completed a full revolution and the press slide has completed a full stroke.Presses equipped with full-revolution clutches are typically older and more hazardous dueto their cycling operation. A part-revolution clutch can be disengaged at any point before thecrankshaft has completed a full revolution and the press slide has completed a full stroke.The majority of part revolution clutch presses use air and a brake. When air is trapped andcompressed in chambers, the clutch is engaged and the brake is disengaged. To stop thepress, the reverse takes place.

    Manually fed presses are cycled either by foot or by two-hand controls or trips. With footcontrols, the press is activated by pressing down on a foot switch or pedal, leaving the hands

    free during the cycling of thepress. This freedom of handmovement places operators usingfoot controls at a greater risk ofsustaining an injury at the point ofoperation. Approximately twice asmany press injuries are from foot-controlled presses. With two-hand

    controls or trips, once a workpiece is positioned in the press,both hands must be removedfrom the point of operation todepress the buttons.

    The other major aspect ofpress operation involves safelyinstalling, removing, andtransferring the dies.

    Rockford Systems Inc

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    Hazard A machine that punches metal in a blink of an eye leaves little to the imagination as to what itcan do to body parts. Severe crushing injuries, amputations, and even death can occur in thepoint of operation or while performing servicing tasks such as die setting or troubleshooting.

     According to Federal Bureau of Labor and Statistics, approximately 7,000 amputations occur

    each year and many are from mechanical and hydraulic presses.

    Flying or ejected parts from either the stock or the dies can also strike operators and otherworkers in the operation area.

    Unprotected operating controls, especially foot pedals, also can introduce the possibility ofaccidental cycling.

    SolutionThe point of operation of all power presses must be safeguarded. Safeguarding isaccomplished either by barrier guarding or the use of devices. Barrier guarding preventsentry into the die area by physically enclosing the point of operation. Devices control entry

    by allowing the operator to reach into the die area to feed or remove parts and will eitherprevent a machine cycle, stop the hazardous down-stroke, or pull the operator’s hands out ifhis or her hands are detected or remain in the point of operation. Guarding is not requiredif the point of operation opening is ¼ inch or less.

    Safeguarding choices for mechanical power presses depend on the clutch systems. Feasiblemethods for full-revolution presses include xed or adjustable barrier guarding, two-handtrips, pullbacks, restraints, or type “A” gates. Part-revolution presses are usually equippedwith barrier guarding, presence-sensingdevices, two-hand controls or trips, type “A”or “B” gates, pullbacks, or restraints. Thesafeguarding options for a part-revolution

    press also can be installed on hydraulicpresses.

    Fixed, interlocked, or adjustable barrierguarding is best for applications where theoperator does not need frequent accessto the point of operation, for example, on amechanical power press in continuous mode. An advantage to using barrier guarding isthat it presents a physical barrier betweenpeople (the operator and other workers)and the machine’s pinch point, in addition

    to capturing any ying parts from eitherthe stock or the die.

    Barrier guarding must be designed and constructed so that people cannot reach over , under ,around, or through the guard and reach the pinch-point hazard. If there are openings in thebarrier guard, the openings must be in compliance with the OSHA (or ANSI) guard-openingrequirements. The following are the maximum permissible openings as listed in Table O-10 ofOSHA’s Mechanical Power Press Standard.

    Power press – continued

    Rockford Systems Inc.

    Barrier guarding on an OBI mechanical power press.

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    Fixed barrier guards are, as the term implies, rmly xed to theframe of the press or the bolster plate, and do not have hinged,movable, or adjustable sections. Interlocked press barrierguarding has hinged or movable sections interlocked withthe clutch/brake control so that the clutch cannot be engagedunless the guard sections are in proper position. When theinterlocked guard section is opened, the press slide must eitherstop immediately or have already completed the die-closingportion of the stroke (full revolution clutch presses normallycannot be equipped with interlocked guarding). Adjustable

    barrier guarding can be adjusted for different material widthsand thicknesses and still meet the acceptable guard openingdistances (Table O-10).

    Devices can be effective safeguards at the point ofoperation. They include presence-sensing devices,two-hand controls or trips, gates, pullbacks, or restraints.Presence-sensing devices (photoelectric “light curtains”are most commonly used) create an invisible sensingeld and are designed to detect an operator’s hand, arm,or other body part entering the hazard area and eitherprevent a machine cycle or stop the hazardous motion

    of the machine. They are a versatile and popular methodof safeguarding because they do not create a physicalbarrier between the operator and the point of operation,they allow complete visibility, and they can be “blanked” or“muted” (certain channels are bypassed) to allow materialmovement. They must be located at the proper safetydistance (see Page 36) from the point of operation andcan only be used on part revolution presses and hydraulicpresses that are capable of quickly stopping hazardous motion.

    It is important to check the “safe distance” of theguard opening to the point of operation. A guardopening scale, like the one above, can be usedto easily determine compliance.

    Rockford Systems Inc

     Adjustable barrier guarding.

    Rockford Systems Inc

    Rockford Systems Inc

    Photoelectric “light curtain” on ahydraulic press.

    Distance of openingfrom point of operation

    hazard (in.):

    Maximum widthof opening (in.):

    1 ⁄ 2 to 11 ⁄ 2

    1 ⁄ 4

    11 ⁄ 2 to 21 ⁄ 2

    3 ⁄ 8

    21

     ⁄ 2 to 31

     ⁄ 21

     ⁄ 231 ⁄ 2 to 5

    1 ⁄ 25 ⁄ 8

    51 ⁄ 2 to 61 ⁄ 2

    3 ⁄ 4

    61 ⁄ 2 to 71 ⁄ 2

    7 ⁄ 8

    71 ⁄ 2 to 121 ⁄ 2 1

    1 ⁄ 4

    121 ⁄ 2 to 151 ⁄ 2 1

    1 ⁄ 2

    151 ⁄ 2 to 171 ⁄ 2 1

    7 ⁄ 8

    171 ⁄ 2 to 311 ⁄ 2 2

    1 ⁄ 8

    The various openings are such that for average-size hands, anoperator’s ngers will not reach the point of operation.

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    Two-hand controls are also used on part-revolution orhydraulic presses and require the use of both of theoperator’s hands to concurrently depress two individualpalm buttons to cycle the machine. These controls mustalso require the operator to hold them down through thedie-closing portion of the stroke (downstroke). Two-hand

    trips are similar to two-hand controls, but are usuallyequipped on full-revolution presses. Trips require onlymomentary actuation of the palm buttons, and oncethe buttons have been actuated, they can be releasedquickly and the machine will make one full cycle or stroke. Ofcourse, locating two-hand controls or trips at their proper safetydistances (see below) are critical for operator safety. Also, theymust incorporate both anti-tiedown and anti-repeat features. Anti-tiedown prevents “tying” one button down and still beingable to cycle the machine by depressing the other. Anti-repeatprevents continuous cycling. If more than one operator isoperating a press, each operator must have their own set of

    controls/trips.Safety distance, as applied to press safeguarding usingpresence-sensing devices, two-hand controls, two-hand trips,and interlocked barrier guards, is a calculation to determinewhere these devices must be located from the point-of-operation hazard so that hazardous motion is effectivelystopped or prevented before contact can be made. Safetydistance is calculated with an equation using the maximumspeed that someone can approach the hazard(63 inches/second) and the total time it takesto stop hazardous motion (seconds). Additional

    factors such as, but not limited to, depthpenetration (presence sensing) and reactiontimes of the control system and safeguardinterface are also included. Stopping time isnormally measured using the brake monitor ora portable stop-time measurement device. The

     ANSI formula takes more factors into accountand normally results in a larger safety distance.

    Gates are movable barriers that enclose (incombination with barrier guards) the point ofoperation before the machine cycle can bestarted, and remain closed until the downstrokehas completed. There are two types: Type “A” gateremains closed during the entire cycle and type“B” gate remains closed during the downstrokeonly. Gates are normally constructed of clearpolycarbonate and powered by air and gravity.

    Pullback devices use a series of cables attachedto the operator’s hands or wrists. Slack is taken up during the downstroke cycle, pulling theoperator’s hands from the point of operation, if they are still there. Restraint (holdout) devicesare also attached to the operator using cables or straps, but must be anchored and adjusted sothe operator’s hands can never reach into the point of operation. 

    Power press – continued

    Rockford Systems Inc.Type “A” gate.

    Rockford Systems Inc.

    Two-hand controls on a part revolution press.

    Press restraints.

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    There is no retracting action involved. Consequently, hand-feeding tools are often necessary ifthe operation involves placing small material into the dies.

    It’s important to remember that most devices do not provide protection from ying parts. Also,control reliability (see Glossary) and a brake monitor (see Glossary) must be incorporated inpart revolution mechanical power presses using a presence sensing device, two-hand control,type “B” gate, or interlocked barrier guarding.

    Full-revolution mechanical power presses must incorporate a single-stroke (or anti-repeat)feature that allows the clutch to engage and the press to cycle only once each time the footcontrol or two-hand trips are depressed.

    To prevent accidental cycling, effectively cover or guard all hand and foot controls. Foot pedalsmust be attached to a nonslip surface to prevent the pedal from sliding.

    Hand tools can be used for placing and removing material, but they do not replace guarding.

     Appropriate die-setting procedures must be established and followed to ensure the safedesign, handling, installation, and removal of the dies. Safety blocks must be used andenforced. Weekly inspections and regular maintenance of presses, parts, auxiliary equipment,and safeguards must be followed and documented.

    If the back of the press presents a hazard to others, prevent access with a barricade.

    Notication of mechanical power press injury:

     All point-of-operation injuries associated with a mechanical power press must be reportedto Oregon OSHA within 30 days of occurrence. Information such as the type of press, taskperformed, type of safeguards, cause of injury, and feeding method must be provided.

    References

    General Industry

    Oregon OSHA Division 2/Subdivision O, 1910.217 – Mechanical Power Presses

    Oregon OSHA Division 2/Subdivision O, 1910.212 – General Requirements for All Machines

    ANSI B11.1 Safety Requirements for Mechanical Power Presses

    ANSI B11.19 Safeguarding When Referenced by the Other B11 Machine Tool SafetyStandards — Performance Criteria for the Design, Construction, care, and Operation

    NIOSH Publication No. 87-107 “Injuries and Amputations Resulting From Work WithMechanical Power Presses”  (May 22, 1987)

    Oregon OSHA Program Directive A-291 – Machine Guarding: Mechanical Power Presses

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    Power press brakeThese metalworking machines bendand form parts through the use oftooling (dies) attached to a ram orslide and a bed. Metalworking occursby placing stock, primarily sheetmetal, on a bottom die and pressingit with a top die attached to themovable ram.

    Press brakes are mechanically orhydraulically powered, or both (hydra-mechanical brakes combine both).Mechanical (ywheel) press brakesuse either mechanical friction or airfriction clutches that can be disengaged at any point before the crankshaft has completed afull revolution and the press slide has completed a full stroke. By inching and slipping theclutch, these presses allow the operator to drop the slide to the work piece and stop, adjust,or align the work piece, and then complete the stroke. Hydraulic press brakes can normally bestopped at any point in their cycle and the force exerted by the dies can be varied. Operating

    speeds are normally slower than mechanical presses; however , because of their sloweroperating speeds, they are normally not fully automated. Hydra-mechanical press brakescombine hydraulic and mechanical operations into one system.

    Regardless of how the press is powered, the basic operation involves the operator feeding orplacing the stock on the bottom die, positioning the stock properly, and activating the presscycle with hand or foot controls. However, one important difference between mechanical andhydraulic brakes is there is no way to reverse the stroke on mechanical brakes. Although itcan be stopped or inched, the stroke must be completed.

    NOTE: When operating a mechanical press brake, if the ram is not brought back up to or pasttop dead center (crankshaft rotation), the ram may drift back down the wrong way before theclutch re-engages. Not knowing where the ram is in relationship to the stroke is a reasonsome press brake operators lose ngers.

    Operating the press brake is only half of the overalloperation – the other half involves installing,removing, and transferring the dies.

    HazardIf the press brake can bend metal with ease, it isobvious that this same capacity can cause seriousinjuries to operators, including severed or brokenarms, hands, ngers, or any other part of the body.

     Although the actual operation of the press brake does not require the operator to place his or herhands or any part of the body into the point of operation, the close exposure to the closing diesstill creates a signicant risk. In addition, the stock can sometimes “whip” or bend up, creating apinch-point hazard between it and the front face of the slide (A) or possibly “slapping” the operatorif he or she is in the path of the rising material (B).

    Installing and removing tooling provides the most direct exposure in the point of operation asthe operator must place his or her hands between the two dies. The operator’s hands orarms can be severely crushed if the ram fell during setup.

    Unprotected operating controls, especially foot pedals, can also introduce the possibility ofaccidental cycling.

    Press brake

    Steve D. Benson

    thefabricator.com

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    SolutionDue to the exibility needed to fabricate metal on press brakes, it comes as little surprisethat these machines are difcult to guard. Fixed or adjustable barrier-type guarding at thepoint of operation is usually not practical because of the fabrication process, though barrier-type guarding can be used to prevent exposure to the unused portions and ends of tooling.However, feasible safeguarding methods, including presence-sensing devices, two-handcontrols, pullbacks, or restraints, can often be used to safeguard the point of operation

    without reducing productivity.

    Presence-sensing devices (light curtains and lasers) and two-hand controls are the mostcommon types of press brake safeguarding. A presence-sensing device prevents themachine from cycling when the sensing eld is obstructed before cycle initiation and stops

    the downstroke when the sensing eld is obstructed after cycle initiation. Two-hand controls(palm buttons) are designed to keep the operator’s hands from the die area by requiringconcurrent and constant pressure to cycle the machine. Both presence-sensing devicesand two-hand controls must be located at a proper “safety distance” – the distance from thepinch-point hazard so that hazardous motion is stopped or prevented before the operatorcan enter the point of operation.

    NOTE: When using presence-sensing devices, make sure there is no space betweenthe device and the point of operation where an operator can stand undetected. If this is

     possible while maintaining an adequate safety distance, additional protection is requiredsuch as a second light curtain installed horizontally, a pressure-sensitive mat, or a

     physical barrier preventing access.

    Pullbacks and restraints of fer another safeguarding option; these use straps and wristlets tokeep the operator’s hands out of the die area by either “pulling back” the arms and handsduring the downstroke or simply “restraining” or keeping the operator’s arms and hands fromentering the die area. Hand-feeding tools are often necessary when using restraints due tothe limited range of movement.

    NOTE: Please refer to the power press document (Page 33) for more informationon the above safeguards.

    Rockford Systems Inc.

    Presence-sensing device (light curtain) used.

    Cincinnati Inc

    Plastic shield (“end barrier”) preventing entry to the unused portionof full-length dies. Two-hand controls used.

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    If the use of physical barriers or devices is not feasible, safeguarding by “safe distance” ispermitted if the employer meets the conditions described in Oregon OSHA Program Directive A-217 “Guarding: Power Press Brakes.” This safeguarding by maintaining a “safe distance”is limited to one-time-only fabrication of made-to-order or custom-made piece parts, such assmall-quantity runs typically performed in “jobshop” establishments. A “small-quantity run” means

    fabrication of more than one of the same piece partover a continuous timeframe of no more than fourhours per month.

    Under this instruction, the operator and helpersmust not approach closer than necessary and,in no case, closer than four inches to the brake’spoint of operation. The minimum safe distance offour inches must be measured from the exteriorpoint of contact of the brake’s die closestto the worker’s ngers holding and supportinga piece part. Finally, this “Safe Distance

    Safeguarding” program must contain writtenexposure prevention procedures, training,and enforcement criteria.

    If more than one person is needed to operate, only one should be designated as the operatorand controls should be furnished for each person. The operator should always make certainthat any helpers are clear of the press before beginning the operation.

    To avoid being pinched or struck by the work piece “whipping” up, never hold the material overthe top of a previous bend, keep your hands underneath the work piece, and always keep yourface and upper body out of the material’s path.

    Before any tooling can be installed, the ram should be lockedin the shut height position with the ram in its most extendedposition (on the upstroke). Once the press is locked into thatposition, the tooling can slide safely into the press. The gapbetween the ram and the bed should be just big enough toallow easy installation without the tooling falling out. Use safetyblocks where tooling permits. Make sure the back gauge is highenough to prevent the piece part from slipping over the top of it,which can bring the operator’s hands and arms into the die.

    To prevent accidental cycling, effectively cover all hand andfoot controls.

     As with any power press, a “no hands in die” policy should

    always be encouraged. Of course, there are times duringsetup where this exposure will occur and effective die settingprocedures or energy-control procedures will address this.Furthermore, the safeguarding devices and strategies mentioned here should keep theoperator’s hands and other body parts out of the die area during operation. Never reachbetween the tooling for any reason – reach around or walk behind the press brake whennecessary. Barricade the back of the press to restrict access.

    NOTE: Consider feasible safeguarding or proper material holding techniques if operating a press brake within a stationary ram and a sliding bed.

    QMF Solutions

    Qualied and attentive operators are a must inmaintaining safe press brake operations.

    Rockford Systems Inc.

    Power press brake — continued

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    References

    General Industry

    Oregon OSHA Division 2/Subdivision O, 1910.212 – General Requirements for All Machines

    Oregon OSHA Program Directive A-217 – Guarding: Power Press Brakes

    ANSI B11.3 Power Press Brakes – Safety Requirements for Construction, Care, and Use

    ANSI B11.19 Safeguarding When Referenced by the Other B11 Machine Tool SafetyStandards – Performance Criteria for the Design, Construction, Care, and Operation

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    Power roll forming and bending machineConventional metal forming and bendingmachines, also known as plate bending rolls,produce smooth, circular bends in sheet, strip,or coiled stock. Metal is fed between successivepairs of rolls that progressively bend and formit until the desired shape and cross section isobtained. The radius of the bend can be adjustedby changing the location of the rolls. Thesemachines are normally equipped with instantstart, stop, and reverse controls.

    HazardSevere crushing injuries, amputations, and evendeath can occur if a worker is caught and drawninto the counter-rotating infeed rolls. The risk ofinjury is high during the initial feeding of the stock.

    Wearing gloves with ngertips and loose clothing also increase the risk of entanglement.

    Workers can also be struck by the moving work piece or pinned between itand a xed structure.

    SolutionInstalling xed or adjustable barri